Plant A is located at the (X, Y) coordinates of (100, 200) and has a volume of shipping of 500 units a day. Plant B is located at the (X, Y) coordinates of (150, 400) and has a volume of shipping of 200 units a day. Using the centroid method, which of the following is the X coordinate for the new plant location? A) About 208.
B) About 227.
C) About 243.
D) About 389.
E) X coordinate cannot be computed from the data given.

An automobile assembly line operation has a scheduled mean completion time, μ, of 12 minutes. the standard deviation of completion times is 1.6 minutes. it is claimed that, under new management, the mean completion time has decreased. to test this claim, a random sample of 33 completion times under new management was taken. the sample had a mean of 11.2 minutes. assume that the population is normally distributed. can we support, at the 0.05 level of significance, the claim that the mean completion time has decreased under new management? assume that the standard deviation of completion times has not changed.